Exemplary embodiments of the present invention relate to a method for detecting an operating motion for an operating device of a motor vehicle equipment item and the operating device of the motor vehicle equipment item.
The use of gesture or motion-based operating actions in a vehicle is already known. U.S. Patent Document US 2010/0185341 A1 describes a method and a device for activating a vehicle operational mode. It concerns spatial and time-based or non-time-based gesture recognition by detecting motions coupled with a comparison with a predetermined gesture. The disclosed method comprises visual monitoring of predetermined locations within or near the vehicle, detecting of a predetermined gesture within one of the predetermined spatial locations, and activating the predetermined vehicle operating mode in response to the predetermined gesture and a present vehicle operating mode. The corresponding device thus has one or more sensors to visually monitor the various spatial locations, and a control device connected thereto.
Beside such visually operating sensors, capacitive sensors for detecting gestures of proximity or touching are also known. For example, four capacitive sensors are used to operate functional units in a vehicle, the sensors being arranged in the corners or at the midpoints of the sides of a square in order to detect operating gestures. The use of four sensors, considered necessary to clearly detect a single gesture as an intended operating gesture, does, however, take significant space. Given the cramped space available in a vehicle, this may be possible only with difficulty or not at all, depending on the type of operating device.
Exemplary embodiments of the present invention are directed to a method and an operating device for detecting an operating motion that enable reliable detection of an operating motion with a reduced number of sensors.
According to a first embodiment, a method for detecting operating motion for sensor-controlled activation of an operating device for at least one motor vehicle equipment item, comprising at least two capacitive sensors having overlapping detection areas that provide signals to a control device to control the at least one equipment item, comprises the following steps: determining at least one direction of the operating motion within the overlapping detection areas as a valid motion direction for operating the motor vehicle equipment item, detecting a motion through the detection areas of two of the sensors and determining a total duration of the motion through the detection areas using the control device, detecting an overlap duration of the motion in an overlapping area of the overlapping detection areas, calculating a quotient from the overlap duration and the total duration, comparing the quotient with a predetermined threshold separating a valid area from an invalid area, wherein the threshold is determined by a ratio of a segment of distance through the overlapping area to the total distance through the detection areas aligned with the segment of distance, and determining whether the motion constitutes an operating motion with a valid direction of motion, if the quotient is in the valid area.
In the first embodiment of the method, detecting of a motion carried out by a vehicle passenger enables sensor-controlled activation of an operating device for a motor vehicle equipment item. Only two capacitive sensors arranged relative to each other to have overlapping detection areas are required to detect an activation motion.
Thus, only two sensors are required for the space-efficient detection of an operating motion, so that a simple space-efficient operating device can consist of just two sensors, if only one equipment item is to be operated and the total equipment required kept to a minimum. If the operation of more than one equipment item is intended, it is also possible to employ the method with more than two sensors, e.g. three or four, whereas one valid operating gesture for one of the equipment items can be determined between two sensors.
If a motion such as a “wiping motion” or another gesture is made, for example, by a hand, the capacitive sensors supply signals to a control device to control the equipment item. The detection method according to the invention now comprises, after at least one direction of the activation motion within the overlapping detection areas has been determined to be a “valid” motion direction intended to result in the operation of the vehicle equipment item, detecting a motion through the overlapping detection areas of at least two of the sensors and determining the total duration of the motion through the detection areas using the control device. At the same time, an overlap duration of the motion is determined in the area in which the detection area overlap. From the overlap duration and the total duration a quotient is constituted, which is compared with a predetermined threshold that separates a valid area from an invalid area. The threshold is determined by a ratio of segment of distance through the overlapping area to the total distance through the detection areas aligned with the segment of distance. From the comparison of the quotient with the predefined threshold it can be determined whether the quotient is within the valid area. If this is the case, the motion is determined as an activation or operating motion with a valid motion direction such that the operation of the motor vehicle equipment item is activated.
Thus, if more than two sensors are intended with multiple variants of valid operating gestures for various equipment items, the control device can, depending on the number of sensors, distinguish at least two valid motion directions between different pairs of sensors to activate the operating devices for at least two motor vehicle equipment items.
Thus, if it is intended that the operating device is to activate more than one equipment item, the method can be performed with more than two sensors, e.g. three or four, wherein advantageously different operating gestures for operating various equipment items can now be detected and distinguished.
Thus, with this method of evaluation, valid motions for an operating gesture can be distinguished from invalid motions by using only two sensors. This is advantageous if more than two sensor electrodes, such as the standard four sensor electrode set, cannot be used for reasons of cost or space, and also makes it possible if more than two sensors are used to distinguish between multiple valid operating gestures.
In a further aspect the valid motion direction for operating the motor vehicle equipment items is within the overlapping detection areas substantially in parallel to a line running between the center points of two sensors, i.e., along those between which a valid motion direction is defined, wherein the valid area is below the threshold. This means that, if the quotient of overlap duration to total duration is smaller than the threshold, an operating motion with valid motion direction is given. If, on the other hand, the quotient of overlap duration to total duration is larger than the threshold value, as is the case for a motion perpendicular to the valid longitudinal direction through the overlapping area, this is an invalid motion direction, and no activation of the equipment item results.
The sensor-controlled operating device according to the invention for one or more motor vehicle equipment items comprises sensors with overlapping detection areas and a control device connected to receive signals from the sensors for controlling the equipment item. The sensors of the operating device are two capacitive sensors that serve to transmit signals to the control device. The control device comprises a signal processing function, by which the method for detecting an operation motion may be effected.
In an embodiment according to the invention, the operating device may comprise four sensors, arranged in a tetragon, wherein the valid motion directions for the sensor-controlled activation of a single equipment item are respectively determined between two of the sensors.
It may be provided that one valid motion direction is determined between two sensors adjacent in the tetragon, wherein a first valid motion direction is substantially perpendicular to a second valid motion direction. It is conceivable that an equipment item might be operated with an operating gesture along the first valid motion direction, independent of which sensor pair this gesture would run along. The same would apply for the second valid motion direction. Alternatively, more than two equipment items could be activated with operating gestures along the first and second valid motion directions, if, in addition to distinguishing between a first and second motion direction and a valid and invalid motion direction, a particular sensor pair is determined for the operating of an equipment item.
In addition to the valid motion directions running between two sensors along the sides of the tetragon, at least a third valid motion direction may also be designated, defined between two sensors diagonally opposite to one another in the tetragon. To perform the method according to the invention by using the diagonally opposite sensors, the detection areas of the diagonally opposite sensors have to overlap.
To carry out the method according to the invention, the control device may comprise a data processing unit that executes the signal processing function, and in which the threshold is stored.
The operable equipment item may be a lighting device capable of being turned on and off if a valid motion is detected by the sensors, however it can be movable motor vehicle equipment items, such as a roof segment, a window, a door, or a trunk lid, which could be opened, closed, or (in the case of a seat) adjusted accordingly.
Thus, the sensor-controlled operating device could be, for example, a roof-mounted “roof operating unit”, which can be made to operate an equipment item with the use of only two capacitive sensors also with gesture recognition.
If the roof operating unit comprises four sensors, various equipment items such as driver and passenger-side lights or reading lamps and an interior light can be operated by gestures. A driver-side lighting device can then be operated with a motion along the first valid operating direction between a first sensor pair, the passenger-side lighting device with a motion substantially in parallel to the first valid operating direction between a second sensor pair, while the interior lighting device can be operated with a motion along the second valid operating direction between a sensor of the first sensor pair and a sensor of the second sensor pair adjacent thereto.
Also disclosed is a motor vehicle having operable vehicle equipment items, and having for this purpose at least one sensor-controlled operating device according to the invention. If the motor vehicle has multiple operable equipment items, the operating device may have at least three sensors to differentiate at least two valid operating directions, or e.g. one sensor-controlled operating device with only two sensors may be provided for each equipment item.
These and further advantages are set forth below in the following description, with reference to the accompanying figures. The reference to the figures in the description serves to support the description and ease understanding of the subject matter of the invention. The figures represent merely a schematic representation of an embodiment of the invention.